1. Field of the Invention
The present invention relates to a recording tape cartridge accommodating, within a case, a single reel on which is wound a recording tape, such as a magnetic tape or the like, which is used as a recording/playback (read/write) medium mainly for computers or the like.
2. Description of the Related Art
Conventionally, recording tape cartridges (magnetic tape cartridges) have been known in which a magnetic tape, which serves as a recording tape and which is used as a data recording/playback medium for computers or the like, is wound on a single reel, and the reel is accommodated within a case formed of a synthetic resin. A leader member such as a leader pin, a leader tape, or a leader block is fixed to the distal end (the free end) of the magnetic tape. A pull-out means provided at a drive device pulls the leader member out from an opening of the recording tape cartridge, and causes the magnetic tape fixed thereto to be taken-up onto a take-up reel of the drive device.
A circular opening is formed in the bottom surface of the recording tape cartridge. A reel gear is formed in an annular form at the center of the bottom surface of the reel which is exposed from this opening. The reel is driven to rotate by a driving gear, which is provided at a driving shaft of the drive device, meshing with the reel gear. Accordingly, by rotating the reel of the recording tape cartridge synchronously with the take-up reel of the drive device, data can be recorded onto the magnetic tape, or data recorded on the magnetic tape can be played back.
In a recording tape cartridge having such a structure, the leader member is a connecting member which connects the magnetic tape to the take-up reel of the drive device in the state in which the magnetic tape is drawn-out. However, the position of the opening formed in the case, and the type of the door or the like which opens and closes the opening, differ for each type of leader member. For example, in a case in which a leader block is used, the opening is formed in a corner portion at the side in the direction of loading the recording tape cartridge (the case) into a drive device, and the leader block is anchored so as to close the opening. Namely, the leader block is structured so as to function also as a door which closes the opening.
Because such a leader block is formed as a rigid body, as compared with a leader tape which is in the form of a tape, there are the advantages that the operation of engaging with the pull-out means of a drive device can be carried out easily and it is difficult for the engaging portion thereof to become worn or to be broken. Further, when the opening is at a corner portion of the case, there is the advantage that the pull-out angle of the leader block can be freely designed at the drive device. For example, the pull-out angle can be designed such that the leader block is pulled out over the shortest distance with respect to the take-up reel, and can be designed such that the operation of pulling out the magnetic tape is completed in a short time.
However, when the leader block is anchored at a corner portion of the recording tape cartridge (the case), if an impact is applied to that corner portion due to the recording tape cartridge being dropped or the like when the recording tape cartridge is not in use (is not loaded in a drive device), there is the problem that the case flexurally deforms, and it is easy for the leader block to come off of the corner portion.
When there is the concern that the leader block may come off of and fall out from the case due to the recording tape cartridge being dropped or the like, the user is led to fear that the functions of the recording tape cartridge itself may be affected, and fear that the recording tape cartridge may not operate in a drive device even if repaired manually. Moreover, when the recording tape cartridge is actually dropped, there are cases in which the leader block comes off from the case, and creases are formed in the magnetic tape. In addition, if the leader block inadvertently comes off, because the leader block itself functions as a door, there is the problem that the dustproof quality of the recording tape cartridge will be insufficient.
Therefore, conventionally, it has been thought to, for example, purposely mold the corner portion in a configuration which easily flexurally deforms, and thereby mitigate the impact due to a drop or the like, and keep the effects on the leader block to a minimum. However, this structure alone is insufficient as a countermeasure for preventing the leader block from coming out from the case.
Thus, as shown in FIG. 10 for example, it has been thought to form an opening 78 in a peripheral wall 74 at the side in the direction of loading a recording tape cartridge 70 (a case 72) into a drive device, at a position other than a corner portion 76, and to anchor a leader block 80 so as to close the opening 78 (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2002-298541). With such a structure, even if, due to dropping or the like, an impact is applied to the corner portion 76 and the case 72 flexurally deforms, it is difficult for the leader block 80 to come out from the opening 78 because the opening 78 is provided at a position which is set apart from the corner portion 76.
However, when the leader block 80 shown in FIG. 10 closes the opening 78, the leader block 80 is flush with the peripheral wall 74, and is anchored so as to structure a portion of the peripheral wall 74. Therefore, there are the problems that the size of the opening 78 must be formed so as to match the size of the leader block 80, and that, when the recording tape cartridge 70 is not in use, it is easy for the leader block 80 to be scratched or the like because it is always in a state of being exposed to the exterior. Because the leader block 80 is a connecting member which is connected to the take-up reel of a drive device as described above, it is not preferable for the dimensional accuracy thereof to be disturbed due to damage or the like.